1 files changed, 64 insertions, 0 deletions
diff --git a/tests/functional/i/invalid/invalid_bytes_returned.py b/tests/functional/i/invalid/invalid_bytes_returned.py
new file mode 100644
index 000000000..703fea278
--- /dev/null
+++ b/tests/functional/i/invalid/invalid_bytes_returned.py
@@ -0,0 +1,64 @@
+"""Check invalid value returned by __bytes__ """
+
+# pylint: disable=too-few-public-methods,missing-docstring,no-self-use,import-error, useless-object-inheritance
+import six
+
+from missing import Missing
+
+
+class FirstGoodBytes(object):
+    """__bytes__ returns <type 'bytes'>"""
+
+    def __bytes__(self):
+        return b"some bytes"
+
+
+class SecondGoodBytes(object):
+    """__bytes__ returns <type 'bytes'>"""
+
+    def __bytes__(self):
+        return bytes("123", "ascii")
+
+
+class BytesMetaclass(type):
+    def __bytes__(cls):
+        return b"some bytes"
+
+
+@six.add_metaclass(BytesMetaclass)
+class ThirdGoodBytes(object):
+    """Bytes through the metaclass."""
+
+
+class FirstBadBytes(object):
+    """ __bytes__ returns bytes """
+
+    def __bytes__(self):  # [invalid-bytes-returned]
+        return "123"
+
+
+class SecondBadBytes(object):
+    """ __bytes__ returns int """
+
+    def __bytes__(self):  # [invalid-bytes-returned]
+        return 1
+
+
+class ThirdBadBytes(object):
+    """ __bytes__ returns node which does not have 'value' in AST """
+
+    def __bytes__(self):  # [invalid-bytes-returned]
+        return lambda: b"some bytes"
+
+
+class AmbiguousBytes(object):
+    """ Uninferable return value """
+
+    __bytes__ = lambda self: Missing
+
+
+class AnotherAmbiguousBytes(object):
+    """Potential uninferable return value"""
+
+    def __bytes__(self):
+        return bytes(Missing)